Forest Management
Invasive Species: Noxious Weeds & Aquatics
An invasive species is defined as a plant, animal, or microbe, including its seeds, eggs, spores or other biological material that is non-native to the ecosystem under consideration and whose introduction causes, or is likely to cause, economic or environmental harm or harm to human health.
The goal of the US Forest Service invasive species program is to reduce, minimize, or eliminate the potential for introduction, establishment, spread, and impact of invasive species across all landscapes and ownership.
Salmon-Challis Forestwide Integrated Weed Management -Implement adaptive and integrated invasive plant management on current and potential infested areas which would include inventory and assessment designed to support Early Detection Rapid Response, control methods, monitoring, and rehabilitation.
Salmon-Challis National Forest contacts:
Katie Baumann (Salmon)- katherine.baumann@usda.gov - (208)-366-9768
Diane Schuldt, North Zone (Salmon) - diane.schuldt@usda.gov - (208)-421-8484
Tommy Gionet, South Zone (Challis) - tom.gionet@usda.gov - (208) 879-4116
Noxious weeds are undesirable exotic plant species which have the ability, due to their invasive nature, to significantly affect entire ecological watersheds, physically alter the environment, and impact visitor’s experiences. Noxious weeds have a direct influence on biodiversity. They affect plant species diversity by displacing native and desirable plant communities, and impact fish and wildlife populations supported by those communities.
Noxious weeds can displace native plants, interfere with land and water use, and affect human and animal health. Weeds not native to an area are of special concern because there are no natural or ecological controls, such as insects or disease, to limit their spread.
In addition to impacting literally all of the plant and animal communities within the area, infestations of noxious weeds (particularly large ones) can greatly affect soil, watershed stability and erosion rates. Noxious weeds can also change normal fire patterns and other big picture ecosystem functions such as nutrient cycling.
Noxious weeds can also change normal fire patterns and other big picture ecosystem functions such as nutrient cycling that directly affect the Frank Church – River of No Return Wilderness and Wild and Scenic Rivers.
The size and extent of noxious weed infestations within the Middle Fork of Salmon corridor may directly or indirectly affect:
- The number of clear water days, which effects both fishing and navigation.
- The amount and types of wildlife seen in the river corridor.
- The amount and quality of areas suitable for camping.
- The number and diversity of flowering plants observed.
- Size, extent and frequency of tributary blowouts.
There are several noxious weed species present in the river corridor. Rush Skeletonweed (Chondrilla juncea) and Spotted Knapweed (Centaurea maculosa) currently are the most aggressive and pose the greatest threat. The USDA Forest Service in conjunction with various partners manages these and other noxious weed species in the river corridor utilizing an Integrated Weed Management strategy. The Middle Fork Ranger District can provide additional information about noxious weed infestations and species within the river corridor, the Integrated Weed Management strategy and ongoing partnerships.
What you can do to help:
- Learn to identify noxious weed species that occupy lands in the areas where you live and recreate.
- Clean your clothing and equipment prior to and directly after use in areas with noxious weeds to prevent the spread of weed seed to new areas.
- Avoid traveling through or camping in areas infested with weeds.
- Report sightings of noxious weeds.
The Forest Service and Bureau of Land Management, along with our many partners, use aerial application treatments to reduce continuous fine fuels in the form of invasive annual grasses (e.g. cheatgrass) and to protect and improve wildlife habitats by treating both invasive annual grasses and noxious weeds.
Aerial herbicide treatment on invasive annual grasses like cheatgrass is excellent with control consistently at or above 90 percent. Likewise, herbicide application control of noxious weeds such as spotted knapweed is well above 90%. Monitoring shows that control persists for several years before retreatment to reduce viable seed remaining in the soil becomes necessary.
This photo shows the clear delineation between treated and untreated areas roughly nine months after aerial application. The light brown area to the left was not treated, and cheatgrass was left to out-compete native bunchgrasses. The darker area to the right is part of a 2021 treatment unit on the north side of lower Fourth of July Creek. Native bunchgrasses did well in this area in Spring 2022 because they didn't have to compete with cheatgrass for survival.
- Aerial Application Frequently Asked Questions (Updated September 2023
- 2024 Treatment Area Map
- 2021 Monitoring Report Summary
- Drift Card Procedures and 2021/2022 Results
- Herbicide Labels for Milestone and Plateau
- Forest Service and Bureau of Land Management Pesticide Use Proposals
- Past Treatment Area Maps
- Conserve Our Western Roots
- Cheatgrass Challenge Guide for Idaho
- Native Plant Communities Restoration-Invasive Annual Grass/ Noxious Weeds Aerial Treatment Private Landowner Opt‐In Cooperative Agreement
Wagonhammer – Bell 206 Long Ranger treating large, contiguous infestations of cheatgrass at a landscape-level in the lower Wagonhammer drainage in 2020.
Polka Dots: Buster Gulch - Bell 47 helicopter spraying polka dot patches of cheatgrass in the upper Buster Gulch drainage in 2018. These separate patches are rapidly merging into contiguous, large infestations.
Head of Deadwater Gulch 7 months post-treatment – Photo depicts cheatgrass control following aerial herbicide application the previous fall. The spaces between native bunchgrasses are no longer occupied by cheatgrass. Temporary herbicide effects in the form of twisted leaves and reduced flowering and seed production can be seen on the arrowleaf balsamroot, a native forb that is a dominant member of the plant community. These effects are temporary and fade the following year. Note that there is no sagebrush in this drainage; it burned in the 2012 Mustang Fire.
This picture shows a native bunchgrass plant community heavily infested with cheatgrass prior to aerial herbicide application. The spaces between the native bunchgrasses are fully occupied by cheatgrass. This creates a continuous fuel bed that rapidly carries fire, creating more frequent and more extensive burns. Our plant communities do not have native annual grasses and are not adapted to deal with this new kind of fire behavior. Note that this plant community has very few forbs and shrubs, having burned multiple times in recent decades, most recently in the Mustang Fire of 2012.
This picture depicts the change in fuel loading when cheatgrass is removed from the plant community with aerial application. There is no longer the uninterrupted fine fuels created by cheatgrass litter. The spaces between bunchgrasses are a normal and desirable part of the native plant community. Over time, as the plant community recovers, biological soil crusts will begin to re-form, protecting the soil from erosion and holding moisture within the soil. If fire frequency and severity decline, native shrubs and forbs will begin to return, re-establishing a functioning native plant community.
AIS are spreading rapidly across the nation, choking rivers, streams, lakes and reservoirs. Cleaning all equipment thoroughly and allowing time to dry between water bodies is key to reducing the spread of these organisms.
National Invasive Species Information Center
Welcome To the Idaho Weed Awareness Campaign!
Pacific Northwest Weed Management Handbook: An excellent source of information about invasive species, invasive species management techniques, and herbicide use.